Formula feeding potentiates docosahexaenoic and arachidonic acid biosynthesis in term and preterm baboon neonates

Infant formulas supplemented with docosahexaenoic acid (DHA) and arachidonic acid (ARA) are now available in the United States; however, little is known about the factors that affect biosynthesis. Baboon neonates were assigned to one of four treatments: term, breast-fed; term, formula-fed; preterm (155 of 182 days gestation), formula-fed; and preterm, formula+DHA/ARA-fed. Standard formula had no DHA/ARA; supplemented formula had 0.61%wt DHA (0.3% of calories) and 1.21%wt ARA (0.6% of calories), and baboon breast milk contained 0.68 ± 0.22%wt DHA and 0.62 ± 0.12%wt ARA. At 14 days adjusted age, neonates received a combined oral dose of [U- ¹³C]α-linolenic acid (LNA*) and [U- ¹³C]linoleic acid (LA*), and tissues were analyzed 14 days after dose. Brain accretion of linolenic acid-derived DHA was ∼3-fold greater for the formula groups than for the breast-fed group, and dietary DHA partially attenuated excess DHA synthesis among preterms. A similar, significant pattern was found in other organs. Brain linoleic acid-derived ARA accretion was significantly greater in the unsupplemented term group but not in the preterm groups compared with the breast-fed group. These data show that formula potentiates the biosynthesis/accretion of DHA/ARA in term and preterm neonates compared with breast-fed neonates and that the inclusion of DHA/ARA in preterm formula partially restores DHA/ARA biosynthesis to lower, breast-fed levels. Current formula DHA concentrations are inadequate to normalize long-chain polyunsaturated fatty acids synthesis to that of breast-fed levels.